Fabrication of Bi₂Sr₂Ca₁Cu₂O_8+δ/Bi₂Sr₂Nd₁Cu₂O_8+δ/Bi₂Sr₂Ca₁Cu₂O_8+δ Josephson Junctions

Abstract

Sandwich-type Josephson junctions using Bi-based oxide barriers were successfully fabricated. Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ films were used for superconducting electrodes, and Bi 2 Sr 2 Nd 1 Cu 2 O 8+δ films were used for the barrier layers. Each material had the same crystalline structure. The resistivity values of the Bi 2 Sr 2 Nd 1 Cu 2 O 8+δ films were rather high compared to those of ordinary metals or Bi 2 Sr 2 Cu 1 O 6+δ . The junctions clearly exhibited S / N / S -type characteristics. We observed the ac Josephson effect on the I-V curves under the irradiation of microwaves around 12 GHz.